[Non Risolto] Cross Table Update o anche Join Update non vanno, 0 righe modificate...

Salve a tutti! Ho un problema con un update MySQL affetta da JOIN.
Di fatti, se eseguo la seguente select:

SELECT * FROM `site_animes` AS `Row` LEFT JOIN  (SELECT `forum_users`.`user_id`, `forum_users`.`username` FROM `forum_users` AS `forum_users`)  AS `User` ON `Row`.`user_id` = `User`.`user_id`  LEFT JOIN `site_anime_producers` AS `AnimeProducer` ON `Row`.`producer_id` = `AnimeProducer`.`id`  LEFT JOIN `site_languages` AS `Language` ON `Row`.`language_id` = `Language`.`id`  WHERE `Row`.`id` = 2

Ottengo dei risultati validi, ma se provo ad eseguire la seguente update:

UPDATE `site_animes` AS `Row`, `forum_users` AS `User`, `site_anime_producers` AS `AnimeProducer`, `site_languages` AS `Language` SET `AnimeProducer`.`name` = 'Fairy Tail' WHERE `Row`.`id` = '2' AND `Row`.`user_id` = `User`.`user_id` AND `Row`.`producer_id` = `AnimeProducer`.`id` AND `Row`.`language_id` = `Language`.`id`

oppure la seguente:

UPDATE `site_animes` AS `Row` LEFT JOIN  (SELECT `forum_users`.`user_id`, `forum_users`.`username` FROM `forum_users` AS `forum_users`)  AS `User` ON `Row`.`user_id` = `User`.`user_id`  LEFT JOIN `site_anime_producers` AS `AnimeProducer` ON `Row`.`producer_id` = `AnimeProducer`.`id`  LEFT JOIN `site_languages` AS `Language` ON `Row`.`language_id` = `Language`.`id`  SET `AnimeProducer`.`name` = 'Fairy Tail' WHERE `Row`.`id` = '2'

Mi ritorna sempre 0 righe modificate, anche se la riga con id 2 esiste.... sapete dirmi il perchè per favore?

Tabella site animes:


Ciao,
Mattia.